Vitamin C: prospective functional markers for defining optimal nutritional status

Area of Science:

• Nutritional Science
• Biochemistry
• Human Health

Background:

• Humans cannot synthesize ascorbic acid (vitamin C), making it an essential dietary nutrient.
• The precise relationships between vitamin C intake, body status, and overall health remain incompletely understood.
• Existing evidence suggests a correlation between higher vitamin C intake and reduced disease risk.

Purpose of the Study:

• To review the relationship between vitamin C intake, body stores, and its role in human health.
• To define the requirements for reliable functional markers of vitamin C status.
• To examine potential molecular, biochemical, and physiological markers for assessing vitamin C status.

Main Methods:

• Literature review of vitamin C intake, status, and health relationships.
• Definition of criteria for reliable functional markers of vitamin C status.
• Description and examination of candidate functional markers across molecular, biochemical, and physiological classes.

Main Results:

• Current recommended vitamin C intake may not ensure optimal status, highlighting a need for clearer definitions.
• An intake of 200 mg/day appears to saturate tissues and maintain plasma levels above a threshold for reduced cardiovascular disease (CHD) risk.
• Defining 'optimal vitamin C status' requires the development and validation of functional markers.

Conclusions:

• Optimal health likely requires optimal vitamin C status, which in turn depends on adequate dietary intake.
• Further research into reliable functional markers is crucial for defining optimal vitamin C status and potentially revising dietary recommendations.
• Establishing clear definitions and validated markers will advance our understanding of vitamin C's role in human health.